[ECOS] Question about the virtual vector? Thanks

[ECOS] Question about the virtual vector? Thanks

[Qiang Huang]

Hi all:
    I got confused by the virtual vector, can anyone give me some help?
Thanks a lot.

e.g.

hal_if.h

__call_voidCOMM1(IF_PUTC, void, __comm_if_putc_t, cyg_uint8)

#define CYGACC_COMM_IF_PUTC(_t_, _c_) \
 __call_COMM_IF_PUTC(_t_,_c_)

// expanded as following
static __inline__  void   __call_COMM_IF_PUTC(hal_virtual_comm_table_t t,
cyg_uint8  _p1_)        \
{                                                               \
    void *dp = (__comm_if_ch_data_t)t[CYGNUM_COMM_IF_CH_DATA];  \
    _ENTER_MONITOR();                                           \
    ((__comm_if_putc_t)(t[CYGNUM_COMM_IF_PUTC]))(dp, _p1_);
\
    _EXIT_MONITOR();                                            \
}

// fill the virtual vector table
#define CYGACC_COMM_IF_PUTC_SET(_t_, _x_) \
 (_t_)[CYGNUM_COMM_IF_PUTC]=(CYG_ADDRWORD)(_x_)

in
"void cyg_hal_diag_mangler_gdb_init(void)" function

CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_diag_mangler_gdb_putc);

expanded to:
(*comm)[3] = (CYG_ADDRWORD)(cyg_hal_diag_mangler_gdb_putc)

so when called to 1). CYGACC_COMM_IF_PUTC --> 2). __call_COMM_IF_PUTC -->
3). call the function in the virtual vector table entry [3] --> 4).
cyg_hal_diag_mangler_gdb_putc() --> 5).
cyg_hal_diag_mangler_gdb_flush( ) --> 6).  CYGACC_COMM_IF_PUTC(*__chan,
'#');   CYGACC_COMM_IF_PUTC(*__chan, hex[(csum>>4)&0xF]); etc. are called
**** back to 1)****??

**Question**  Will this cause recursive call?? (I looked in the document
about virtual vector but can't find out whether the recursive call will
happen or not?)

BTW for implementing virtual vector table mechanism what HAL function should
I provided??

Thanks a lot.


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